I think there's settling and settling. Marrying someone because they are a kind, decent person, you have respect for them, and you want to create a safe and happy family home is as good a reason to marry as any, really. But marrying someone because you're afraid of being alone - that isn't going to work out.
I've been very lucky. I had all the chemistry and passion with DH at the start, but in hindsight, if he'd been a prick, I would have been fucked because for a variety of reasons I was in a vulnerable position at the time. As the years have gone by, I feel that our love has turned into something deeper and more enduring. I couldn't imagine life without him, he is the one for me. But what has caused our love to become stronger over the years wasn't the sex and passion of the early days, it was watching him with our children, watching him make sacrifices for our family, having him help me when I was struggling. That's nothing to do with how much I wanted to shag him when we first met, though conversely, his kindness and reliability over the years now makes me want to shag him more than ever
so yes, it's a funny one really.